This invention relates to a gunning method in which refractories are suitably coated or filled to construction, vessel and apparatus for which a refractory property is required.
These days unshaped refractories are in quick spread thanks to their effectiveness for the improvement of working efficiency and there are introduced various working methods utilizing vibration, centrifugal force, pressure force, injection, gunning, etc. as well as pouring, and feeding under pressure. Among other things a gunning method holds an important field and there are proposed many improvements for working properties, but there is still left room for further improvements.
For example, the nozzles generally used for apparatus of gunning refractory materials are expendables, and therefore they are of the shape of rectilinear pipe as it is or of the shape in which the end of pipe is bent at an angle of some degree, thus principally being of structure of very simple shape. Moreover, the most nozzles are fixed to a rectilinear pipe connected thereto, so that in gunning refractories by using such nozzles the gunning area is limited to a very narrow one ahead the nozzle and to move the working surface or change the direction of nozzle it is required to change the working position each time.
Accordingly, such gunning method has been very inconvenient and at the same time it has lowered working efficiency as well as being deficient in continuous and homogeneous properties of gunning layers.
As an alternative system there is a gunning method which uses a horizontal type rotary nozzle, but in such case the refractory material is gunned even to other portions than the zone intended to be gunned and this method results in a loss of the refractory material to be uneconomical.